It sometimes appears to me like the OpenSim community isn't used to Blinn-Phong, maybe not even to shiny surfaces in general. Maybe that's because they've rarely been exposed to it over the years. I guess that at least some content that was ripped from SL had normal maps and/or specular maps at the source, but whoever stitched the export back together after importing it into OpenSim often didn't know what to do with them and threw them away. In the rare cases you see Blinn-Phong in action nowadays, it's usually on original OpenSim content.